gms | German Medical Science

Background: Decision making in the event of illness has a major influence on people’s lives. Moreover, patients’ decisions about healthcare fundamentally determine the performance of the overall healthcare system in terms of a population’s health, the quality of healthcare services, and the level of expenditures. Understanding what individuals do or do not do when they experience physical or mental symptoms of illness has therefore been a key topic in medical sociology, health services research, and health psychology. In all disciplines, several prominent models of illness behavior have been developed and used in empirical analysis. Despite the large body of theoretical and empirical research, the debate about the “best” theoretical framework continues.

Research Question: What are the similarities and differences between explanatory models of illness behavior? Do the differences arise from different theoretical assumptions or empirical applications?

Method: We review the key conceptual components of six models of illness behavior: the Health Belief Model, the Protection Motivation Theory, the Theory of Planned Behavior, the Common-Sense Model of Self-Regulation, Andersen’s Behavioral Model of Health Service Use, and the Network-Episode Model. Moreover, we conducted a systematic review of systematic reviews and meta-analysis of these models in ISI Web of Science, PubMed, and PsycInFO/EBSCO. We compare the similarities and differences of how these models are operationalized and utilized in empirical research based on a structured coding scheme.

Results: All models have been applied empirically, mostly in quantitative but also in qualitative research Our analysis indicates that there is a fair overlap in the concepts that these models see as important for explaining illness behavior. However, they differ in the priorities they assign to certain dimensions such as illness cognitions, emotions, and structural conditions (e.g., the healthcare system). We conclude that the models fulfil different purposes by shedding light on specific dimensions of illness behavior, e.g., preventive health behavior (Health Belief Model) or the utilization of healthcare services in the event of illness symptoms (Behavioral Model of Health Service Use). Based on this comparative analysis, we provide a guide for authors how to select a well-suited model and how to assess the strengths but also the limitations of the chosen theoretical approach.

Discussion: Our study shows that each model makes a unique contribution to the study of illness behavior – not mainly because of strong differences in their theoretical assumptions but due to varying operationalizations and empirical applications. We suggest that a knowledgeable application of each model in the right context can help to move research on illness behavior forward rather than the never-ending search of an “integrative framework of illness behavior”.

Practical Implications: Understanding what persons do when they are ill is of crucial importance for understanding and managing healthcare services. Researchers who aim to explain illness behavior should be aware of the strengths and weaknesses of the theoretical models they use in order to draw appropriate conclusions from their analysis.